Originally, Panther 2 only differed from Panther I in armor specifications–roughly January 1943. They were otherwise identical. Later, it was decided to standardize automotive components between Panther 2 (later called Panther II) and Tiger 3 (later called Tiger II)–roughly February 1943.
Panther 2 / Panther II used 660mm wide combat tracks. (Edit: See comment at end of this post.) This is the same width as combat tracks for Panther I. When it was decided to standardize Panther 2 with Tiger 3, it was also decided that the 660mm combat tracks for Panther 2 / Panther II would serve as transport tracks for Tiger 3. It was also decided to use the rubber saving steel wheels from Tiger 3 on Panther 2. However, Panther 2 and Tiger 3 would use different swing arms.
In April 1943, Panther 2 is designated Panther II.
In May 1943, it is decided to shelve Panther II. Some of the design work for Panther II is incorporated into Panther G.
Note that the steel wheel arrangement for a Panther G with steel wheels is different from the arrangement for Panther II.
Design work on Panther F begins in March 1943, independent of Panther 2. This will utilize a new, smaller turret with a smaller front plate, resulting in more protection for less weight. The chassis for Panther F does not change from Panther G. Later, the Panther F chassis gains some small upgrades versus Panther G.
If I am reading Germany’s Panther Tank, The Quest for Combat Supremacy correctly, all versions of Panther have 660mm combat tracks. That never changes through all the versions. Some minor track characteristics, like cleats, do change over time.
Panzer Tracts volumes on Panther may contain updated information that contradicts what is written above. I do not own those volumes and cannot comment on them.
Edit: I just watched a bunch of videos on Panther tracks. According to the people making these videos, Panther II uses a transport track designed for Tiger II, not a track designed for Panther I. The surviving example of Panther II uses a transport track designed for Tiger II. I do not know what is going on here. As with most tank stuff, it is extremely confusing and sources contradict one another.
Edit: This video may help.